Nano-MgO particle addition in silver-sheathed (Bi,Pb)(2)Sr2Ca2Cu3Ox tapes

Nano-MgO particles have been introduced into Bi-2223/Ag tapes fabricated by the rod-in-tube process. The effect of MgO on the high-T-c (Bi-2223) phase formation, microstructure and transport property of the tapes was studied. The DTA measurements showed that the nanometer MgO particles decreased the optimum sintering temperature of the tapes. XRD and SEM analysis indicated that nano-MgO particle increased the low-T-c (Bi-2212) phase fraction in t he tapes and degraded the grain alignment. The electrical and magnetic meas urements showed that nano-MgO had little effect on the critical temperature (T-c) of the tapes. The critical current density (J(c)) of the tapes with moderate MgO doping (similar to 2.5 X 10(4) A/cm(-2)) was higher than that of undoped tapes (similar to 2 X 10(4) A/cm(-2)). The J(c) behavior of dope d samples in magnetic field was significantly improved. (C) 2000 Elsevier S cience B.V. All rights reserved.